The United States has proposed analyzing genetic information from more than 1 million American volunteers as part of a new initiative to understand human disease and develop medicines targeted to an individual's genetic make-up.

At the heart of the "precision medicine" initiative, announced on Friday by President Barack Obama, is the creation of a pool of people — healthy and ill, men and women, old and young — who would be studied to learn how genetic variants affect health and disease.

Officials hope genetic data from several hundred thousand participants in ongoing genetic studies would be used; other volunteers would be recruited to reach the 1 million total.